Rear axle and bearing and oil seal gap.

[MarkyB]

Surely the load on the bearings has more to do with the weight of the car, not the power of the engine?

[philthehill]

Les - I agree unless you are driving mostly sideways then the side loading on the bearings is increased and the more power the more sideways you can go. My Minor when driven round corners is always driven just before the point of the rear end breaking away. Real seat of the pants and opposite lock stuff. Lovely jubbly.

[BLOWNMM]

Hi Phil

Thanks for the tip re lubricating the oil seal. When I assembled the hub I put a smear of Dow Corning ultra high vacuum silicone grease on the seal and its bearing surface on the end of the housing. I reckon this will be enough.

Cheers Bob

[philthehill]

Bob
I would want more than a smear.
Brake dust will dry up the grease and turn it into a abrasive compound.
Personally I would have 3/4 packed the void between seal and bearing with Castrol LM grease (or similar). That would give the same seal lubrication conditions as those found on/at the front hub seal.
Then it would be truly fit and forget.
Phil

[kennatt]

It's shocking really....but in all my years of Minoring I've never had the slightest problem with rear (or front come to think of it) bearings! I must have been extremely lucky!!

Nor me The bearings on my 55,have never been changed in the 30 odd years of ownership ,its on its third gearbox and just about every other mechanical item has been changed. So they must have got the original bearing design right.Not many moderns could claim that.

[alexmcguffie]

Not many moderns could claim that.

Having every other mechanical part replaced other than rear wheel bearings ?

[philthehill]

Those who have never had to change rear hub bearings are extremely lucky.
They do wear out - which may result in roughness of the bearing and slight play at the wheel
There are quite a few posts on this site (522) relating to having rear hub bearing problems, changing the rear hub bearings, the use of lesser grade bearings and the replacement of rear hub seals; so it is not such a rare occurrence as may be thought.

[BLOWNMM]

G'day Phil
I need to remove the axle shafts to check the bearing protrusion, so will take your advice and pack the void with grease. Thanks for the tip.
Cheers Bob

[philthehill]

Bob

By all means put a very very light smear of grease on the lip of the seal before fitting the hub but wipe off all excess on the brake side of the seal when fitted. That little bit of grease will give the hub seal a good start in life but not attract sufficient brake dust to cause problems.
Only pack the void to 3/4 full as you want room for expansion of the grease as it warms up.
Completely pack the void and the seal will leak

Phil

[bmcecosse]

The axle oil will still flow into the hub - along the half shaft... I don't see the need for a load of grease in there - and it may just block up the little drain hole ! I suspect quite a few bearings are changed needlessly...to try to correct leaks that are due to worn seal only. The grease in the 'sealed' bearing may melt - from friction and brake drum heat - and possibly escape past the seals. But will the oil flow back in to keep the bearing lubricated ? I honestly don't see ANY need to move away from the tried and trusted BMC design! The only upgrade I would consider is a double lip seal if the standard seal is proving troublesome.

[philthehill]

bmc
Whilst I appreciate your concerns I personally do not see a problem with Bob's hub bearing and seal arrangement.
Oil can only go over or under the hub bearing as it cannot go through it.
It cannot go over because the bearing is pressed into the hub.
It cannot go under as the bearing sits on the axle casing.
There may be a slight weep over and under the bearing if the axle casing and hub are worn but if it can find its way in it can find its way back out again. The standard hub seal isn't going to let it go any further.
Oil may leak past the gasket and 'O' ring but that is a different matter.
Front brake hubs get very hot due to braking and the hub seals do cope with wide variations of temp and I am sure that the sealed bearing seals will be of adequate heat resisting quality. Bob's sealed bearings seem to have coped well so far.
Even if the seals on the sealed bearing fail what will happen - at the worst you will get oil into the bearing and you will be back to the standard Minor hub bearing/seal arrangement.
I think that Bob's sealed bearing/hub seal arrangement is well worth a try and it may be a solution to the poor quality hub bearing supplied these days.
Bob
Please give us an up date after a few thousand miles of use.
Phil

[bmcecosse]

Poor quality hub bearings?? There are many top quality suppliers of the 6207 bearing (just look on ebay) - no need to buy poor quality - and certainly don't buy the C3 bearings!!! This thread started about leaking rear hubs- the 2RS bearing doesn't help that at all ! The 2RS has no advantage in this enclosed application whatsoever... It's not something I'll be bothering with.... if I ever need to change a rear bearing...which hasn't happened yet in 50 years (on and off) of Minor motoring!

[philthehill]

bmc
I have searched for 6207 bearings on 'e' bay and they are all metric 35mm x 72mm x 17mm and either open, sealed or C3.
The old Minor OE rear hub bearing which I have in front of me is stamped with the following details:-
R & M, Made in England, 40 -M97 on the outer race and on the inner race R & M, 40 - N97, 35L.
The dimensions of the above bearing measured (using an accuracy checked digital vernier) is -
O.D. ...........72.4mm
I.D. ............34.94mm
Depth..........16.93mm

So would you recommend the use of a 6207 metric bearing (no pun intended) in mind the differences in dimensions.
Phil

[alexmcguffie]

Phil,
Interesting your measurements convert exactly to imperial fractional units. I would be very surprised if a metric part could be used as a direct replacement for what would originally have been an imperial part. I might enquire with some bearing experts at work...

Alex

[bmcecosse]

I was going from 'Bob's recommendation for the 2RS bearing he suggested - I assumed the 6207 was the correct bearing. Morris did use metric bearings on the front - wouldn't surprise me if the rears are also metric. I may have a nos rear bearing in one of my many filing cabinets....if I find it, i'll run a gauge over it and report back.

[BLOWNMM]

G'day Phil
The car has travelled 2535 miles since I changed to a 1000 dif so that when I check the bearing protrusion I should have some idea of any problem. Will post back when I do that.
Cheers Bob